Explain the following. A man is told that if he fasts completely for 24 hours he will receive a four-course meal. He is locked into a windowless room that contains only one door, with a small, freshly home-made apple pie on a table in the centre of the room alongside a water tank. After 24 hours, the door is opened to reveal an empty pie dish. The man insists he didn't eat it.

I realised when I was writing it that it doesn't work as well as it does when it's spoken, and asked after a lot of other lateral puzzles. What I think is interesting about it is it's about NOT thinking laterally, which is, in a lateral thinking environment, thinking laterally. Back to the drawing board!